Viswanathan, V., et al. 2018. Why Aren’t There Electric Airplanes Yet? It Comes Down to Batteries. Batteries need to get lighter and more efficient before we use them to power energy-guzzling airplanes. Smithsonian.

“…for a given weight, jet fuel contains about 14 times more usable energy than a state-of-the-art lithium-ion battery….the best batteries store about 40 times less energy per unit of weight than jet fuel. That makes batteries relatively heavy for aviation. Airline companies are already worried about weight – imposing fees on luggage in part to limit how much planes have to carry.”

So what about a flying car (e-VTOL)?

We looked at how much energy a small battery-powered aircraft of 2,200 pounds (1,000 kilograms, including a passenger) capable of vertical takeoff and landing would need. While actually flying, the air vehicle would need 400 to 500 watt-hours per mile, about what an electric pickup truck would need, which is twice as much energy used as an electric car.

But taking off and landing require a lot more power, at least 8,000 to 10,000 watt-hours per trip, or half the energy in a compact electric car such as the Nissan Leaf.

So for an entire flight of 20 miles you’d need 800 to 900 watt-hours per mile — half as much energy as a fully loaded semi-truck. Using that much energy means these aren’t likely to take off.

“Aircraft designers also need to closely examine the power – or how quickly the stored energy is available. This is important because ramping up to take off in a jet or pushing down against gravity in a helicopter takes much more power than turning the wheels of a car or truck.

Therefore, e-VTOL batteries must be able to discharge at rates roughly 10 times faster than the batteries in electric road vehicles. When batteries discharge more quickly, they get a lot hotter. Road vehicles’ batteries don’t heat up nearly as much while driving, so they can be cooled by the air passing by or with simple coolants. But an e-VTOL would generate an enormous amount of heat on takeoff that would take a long time to cool – and on short trips might not even fully cool down before heating up again on landing.

This huge amount of heat will shorten an e-VTOL batteries’ life, make them more likely to catch fire, and require specialized cooling systems that add additional weight and energy demands on the battery.

Schrope, M. 6 Nov 2010. Fly Electric. New Scientist.

A 200-seat airplane weighs about 115 tons at take off.

About a third, or 38 tons of that weight is the kerosene fuel.

The other 77 tons are the passengers, their luggage, and the airplane itself.

An electric, battery-powered airplane would require nearly 3,000 tons of lithium-ion batteries – the batteries would weigh 39 times more than the plane, passengers, and their luggage.

There won’t be any flying cars or battery powered airplanes. JATD (Just Another Techie Dream).

Antius on Wed, 13th Mar 2019 1:50 pm

The energy density of realistic lithium ion batteries is about 1MJ/kg. Energy density of kerosene is over forty times greater. DC electric motors are 80% efficient; high bypass turbofan engines are about 33% efficient. So the effective mechanical energy density for kerosene gas turbine is about 17.5 times greater. Now consider that a gas turbine plane gets lighter as it flies. An electric plane will have about 1/20th the range of a kerosene plane, all else being equal.

Electric planes could in principle replace fossil fuel powered planes for short haul flights. But in practice, their short range severely limits their applicability. A liquefied natural gas powered plane is a far more practical proposition. LPG would be an even better choice. Hydrogen could work too, as any boil off from liquid hydrogen tanks can be vented directly through gas turbine engines.

A hydrogen inflated rigid airship is a workable possibility for short to medium distance flights. Such a ship could burn natural gas in a non-compressed form. Over medium distance flights, it would be far more energy efficient than a jet aeroplane. The problem is that lower speed is problematic in terms of amortization of capital costs. You simply get fewer passenger miles in the average year if you are carrying people at 70mph rather than 500.

peakyeast on Wed, 13th Mar 2019 2:20 pm

@antius: Not only that: The passengers themselves often don’t have the time to waste. Tourism will get much more local with that travel speed.

Cloggie on Wed, 13th Mar 2019 2:37 pm

Can we place have women like Alice Friedman as far away as possible from anything related to technology as possible. Women have contributed exactly zero to technology and science and never will, which is unproblematic in itself.

Its ok neder, you have contributed exactly zero to science and technology and never will either, which is unproblematic in itself.

All of your remarks are ridiculous, no matter what the topic.

Antius on Wed, 13th Mar 2019 3:16 pm

Cloggie, battery electric aeroplanes have very limited applications. 360km won’t even get you from Amsterdam to Paris (430km). And for safety, it is always necessary to maintain reserve fuel margins.

An electric train will get you between any two cities at about the same speed, without the range limitations. So Alice Friedman is quite right to view the idea of electric planes with scepticism. A hydrogen plane would be functionally more effective, but expensive if you are producing hydrogen from electricity and burning it in gas turbines. Solid biomass or biochar, with energy density of 20-30MJ/kg, could be made to work as an aircraft fuel. But is logistically difficult, as we would need to design engines that burn solid fuels.

Suborbital rockets could be a workable solution from an energy efficiency viewpoint. But there are problems with reusability, complexity, safety and political issues.

My guess is that the future will involve less travel, more travel by train and aircraft that run on LPG and liquefied natural gas.

A small nuclear reactor would be a workable solution for powering an airship, as only a few megawatt of drive power are needed for a Hindenburg size ship to cruise at 70mph. Not a workable solution for a jet aeroplane, which needs hundreds of megawatts of power in a very lightweight package. And probably not a politically workable solution for either, at least in the foreseeable future.

Juanita Pee on Wed, 13th Mar 2019 3:17 pm

Cloggie, JuanP is playing games with you

Cloggie on Wed, 13th Mar 2019 3:33 pm

Antius, like with driving, I don’t believe in batteries but in hydrogen/fuel cells to provide for electricity:

“BREAKING NEWS: Trump GROUNDS Boeing 737 Max planes ‘effective immediately’ after U.S. was left as only country in the world still flying them after Ethiopia disaster (but Boeing suggests it asked the FAA to do)”

Antius on Wed, 13th Mar 2019 4:29 pm

“Antius, like with driving, I don’t believe in batteries but in hydrogen/fuel cells to provide for electricity”

Cloggie, hydrogen planes are unlikely to use fuel cells. Converting hydrogen into electricity in a fuel cell and powering electric motors cannot compete with gas turbines on power to weight.

Basically, you are looking at aircraft that are broadly similar in design to existing aircraft, with differences in fuel storage and delivery systems.

I still think liquefied natural gas is a more workable fuel for an aircraft. It is a soft cryogenic that has far fewer issues with materials compatibility, thermal gradients and thermal shock. A liquid hydrogen powered aeroplane would need to insulate its fuel tanks to prevent air from liquefying on contact with them. Not a very easy thing to work with.

You’ll be dead by 2050 you fucking moron. You have no idea what tomorrow will bring let alone 30 years from now. How stupid and ignornat are you lol. Davy must think you are genius of some sort, but he is an inbred hick who doesn’t know what he is taking about either. Trust me I know.

Antius on Wed, 13th Mar 2019 6:00 pm

“Here’s How NASA Thinks Society Will Collapse”

Europe came close to collapse in the middle ages, when plague decimated the population.

European countries became the rulers of the planet by developing new transport systems (sailing ships) that allowed them to unlock the resources of new continents, especially America. The race to exploit these new resources and convert them into new products and wealth, were the driving force behind the industrial revolution. Within a few centuries, Europeans went from being obscure people living in a backwater, to the absolute rulers of the world, colonizing all of it’s empty spaces.

Maybe we can pull it off again? The Earth is fully exploited now. There is nowhere left to colonize here. But the solar system is full of empty space and untapped resources. The race that succeeds in exploiting these resources will be the dominant race of humanity in the indefinite future. That is something that the Chinese and Indians understand only too well.

In 1 line, it says
“for a given weight, jet fuel contains about 14 times more usable energy than a state-of-the-art lithium-ion battery”
in another line, it says
“best batteries store about 40 times less energy per unit of weight than jet fuel”

Dont you feel its contradictory, which 1 is correct, jet fuel has 14 times the energy or 40 times the energy of a battery for a given weight.

The author fails to mention that motors are 3-4 times more efficient than engines and that’s why electric vehicles have 120 – 140 MPGe. What this means is 1 gallon of gasoline generates 33 KWh in a power plant and with this 33 KWh, an electric vehicle travels 120 miles, whereas this 1 gallon of gas in a regular car goes only 30 – 35 miles.

Besides the current aeroplanes are designed for jet engine and not for motors, many startups are working on electric vertical takeoff/landing planes with multiple motors which are far more efficient.

To summarize, electric planes are not far off, they will soon come.

Antius on Wed, 13th Mar 2019 6:29 pm

“Dont you feel its contradictory, which 1 is correct, jet fuel has 14 times the energy or 40 times the energy of a battery for a given weight.”

The difference is due to the fact that DC electric motors are 80% efficient, whereas gas turbines burning diesel are 33% efficient. So, even though batteries contain only 1/40th the energy density, they will yield perhaps 1/14th the mechanical energy, due to the greater efficiency of electric motors.

The energy density is still poor as piss, though not quite as bad as simple comparison of stored energy per unit mass would suggest.

slowermindskeepRight-akafmr-paultard on Wed, 13th Mar 2019 6:30 pm

andrew yang is a libtard so i won’t vote for him but he’s a big potential to cause upset to the political system and survival of whiteys.
as a libtard, like supertard he does not respect (((supremetard))). supertard calls him “sky daddy”.

andrew is a tard so he promised something that (((supremetard))) advised against and that’s tards do not live on bread alone. Normally for someone who is (((supremetard))) fearing, I wouldn’t have problem defending yang’s policy but he can’t.

notice he said it’s a “freedum divident”. this causes mass suicide of basement nazitard because it is not “muh bodily fluid divident”. This is a proposition not a “realist” position

andrew yang is for supertard and so is tulsi gabbard

I AM THE MOB on Wed, 13th Mar 2019 6:30 pm

Antius

Knuckle draggers like you and your great mustard race will be the first to perish..

Get ready for barbarism!

Antius on Wed, 13th Mar 2019 6:50 pm

One possible use for electric aircraft or any other stored-energy aircraft.

An aircraft does not need a lot of range to be useful in this function. It merely needs to reach a ceiling of 40,000 feet (~10km).

Launching a rocket from an aircraft dramatically reduces the size of the rocket needed to reach low orbit. It also makes it much easier to reach orbit using a single stage vehicle, which reduces the complexity and cost of the rocket vehicle.

Presumably, an aircraft designed to carry a rocket to 40,000 feet, release it and then glide back to a horizontal landing site; could be relatively simple and easy to build. The performance requirements are quite modest compared to an aircraft that must fly long distances. However, the craft does need to be large in order to carry a rocket of any significant size.

makati1 on Wed, 13th Mar 2019 7:06 pm

Antius, we all know that electric airplanes are never going to happen. Electric cars are still in the experimental stage….ie…Tesla.

If the author is correct: To replace that with batteries (and forgetting the minor engine weight difference)…you would need a battery that weighs (14X24) about 336 tons or about FIVE times the TOTAL loaded weight of the 777 with jet fuel.

Should Canada increase tariffs on bananas from Guatamala because Guatamalan bananas are cheaper?

Should Japan increase tariffs on oil from Kuwait because Kuwaiti oil is cheaper?

I AM THE MOB on Wed, 13th Mar 2019 9:42 pm

The MSM is Terrified that Ilhan Omar is Bringing the Israel Lobby and Duel Loyalty into Public Discourse…Expect to See More Establishment Lackeys like Meghan McCain Shed tears for their Beloved Genocidal Terrorist State..

I AM THE MOB on Wed, 13th Mar 2019 11:29 pm

I’ve had one desire since I was born

To see my body ripped and torn

To see my flesh devoured before my eyes

Only for you I volunteer as a human sacrifice

Carve me up, slice me apart

Suck my guts and lick my heart

Chop me up, I like to be hurt

Drink my marrow and blood for dessert

Cloggie on Thu, 14th Mar 2019 12:12 am

Energy content (kWh/kilo):

Hydrogen: 33
Kerosine: 12

That’s all you need to know that electric flying is going to work for distances within Europe, America, China, fossil-free.

This is why hydrogen will never be a common fuel in planes or vehicles.

Anonymouse on Thu, 14th Mar 2019 1:54 am

On the contrary, I can think of some important niche applications for hydrogen fuel Mak. I propose CloggYid here have his autonomous robo-wheelchair retrofitted with a liquid hydrogen fuel system (and a pair of wings).

A small wick, which can easily lit with a common match, will provide for the ignition system. Once the wick is lit, and any humans have evacuated the area, Cloggenfraud will finally be able to realize his dream proving the viability of hydrogen powered flight to a skeptical, sneering world, by having (bits and pieces of him anyhow) fly via clean and green hydrogen on a whirlwind to-the-future tour to all his favorite destinations. Be it, the Wailing Wall, Palm Springs, the Anne Frank Museum, w/e. Hell, with a large enough tank, pieces of him might even be able to drop in and pay delusional davy a visit in his bayou swamp on the opposite side of the world.

So yes, I say, strap as much hydrogen fuel as we can under cloggrhamans worthless ass, light em up, and see what happens.

According to my calculations, hydrogen has more than sufficient energy to blow cloggenyid to Yawheh and back with room to spare. Far more efficiently and cleanly than say, Kerosene, which is so 19th century.

You know, for science. Progress. The future.

Cloggie on Thu, 14th Mar 2019 2:30 am

“…the airship was filled with highly flammable hydrogen…”

Nobody advocates storing hydrogen for airplanes in tent cloths, like with the Hindenburg.

This is why hydrogen will never be a common fuel in planes or vehicles.

In Norway cars will be driving on hydrogen soon in large numbers and spread from there.

Hydrogen will begin in Norway because the country is rich (thanks to oil.lol) and because it has hydro-electricity in abundance and population density is low.

And Norway has historically a lot of experience with producing hydrogen from electrolysis:

So yes, I say, strap as much hydrogen fuel as we can under cloggrhamans worthless ass, light em up, and see what happens.

Our African-American friend Anonymouse is precisely the reason why North-America is sinking away into irrelevance. You can’t build or even sustain a higher civilization based on sneers. I’m OK with that. Anonymouse is doing the work of overthrowing the Empire by turning it into a third world hell hole, so we Europeans don’t have to. By the time the number of opium deads per million in the US, currently…

US – 800
UK – 60
EU – 20

…will have reached 1500, whitey is probably going to revolt. We only have to come over and pick up the pieces.

“The US residential sector rebounded after a year in which the sector contracted by 15%, growing by 7% in 2018. The US residential sector has now seen five consecutive quarters of modest growth, with the fourth quarter of 2018 resulting in the largest quarter for the sector in two years, and nearly 315,000 households adding solar for the year. On the other hand, the US non-residential sector declined by 8%, while the utility-scale sector also saw a slight contraction due to the impacts of the Section 201 tariff uncertainty which abounded earlier in the year. All in all, solar PV accounted for 29% of all new electricity generating capacity additions — a lower share compared to 2017 due to a surge in new natural-gas projects earlier in the year.”

“Despite mixed results for 2018, the Wood Mackenzie and SEIA report nevertheless predicts stronger growth in its forecasts from 2020 to 2022. Total installed solar PV capacity is expected to increase in the US by 14% in 2019 with annual installations reaching 15.8 gigawatts (GW) in 2021. Meanwhile, projects for utility-scale solar from 2020 to 2022 now exceed forecasts originally made before the imposition of the Section 201 tariffs.”